The present invention relates to a cold moldable explosive composition and to its preparation process. More specifically it relates to explosive compositions containing a powerful explosive and a thermoplastic binder in the form of a cold moldable powder.
In general, explosive compositions are constituted by an explosive charge dispersed in a thermoplastic or thermosetting binder. The standard procedure for obtaining such compositions is to coat an explosive powder with the thermoplastic or thermosetting binder and to then consolidate the coated powder by compression.
When using a thermoplastic binder in the manner described in U.S. Pat. Nos. 3 173 817 and 3 400 115, it is necessary to perform the compression stage hot.
When thermosetting binders are used in the manner described in French Pat. No. 2 268 770 (Commissariat a l'Energie Atomique), No. 2 144 988 ((French State), No. 2 241 514 (Messerschmitt), No. 2 138 513 (Commissariat a l'Energie Atomique) and No. 2 225 979 (French State), in most cases it is necessary to carry out hot compression in order to obtain the desired characteristics.
Performing the compression stage hot leads to certain problems, when it is wished to bring the explosive composition into a particular form.
Thus, it is necessary in this case firstly to prepare a block by hot compression and then remachine the block obtained. Therefore, the performance of a hot compression stage is technically and economically very onerous.
However, certain explosive compositions coated with thermosetting binders can be compressed cold or extruded in the manner described in European Pat. No. 003 6481 (Delsenroth). In this case, use is made of a polyurethane-based binder and the coating operation is carried out by using an aqueous polyurethane dispersion. However, the coated explosive powder obtained in this way does not have an adequate storage stability and must therefore be rapidly moulded. Thus, thermosetting binders are not stable over a period of time, because they slowly crosslink and polymerize, which is prejudicial for the subsequent performance under satisfactory conditions of the compression stage of the binder-coated explosive powder.